Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatitis C virus (HCV) is a major cause of post-transfusion and sporadic hepatitis worldwide, leading to chronic liver disease in at least 50% of infected individuals. The pathogenic mechanisms that result in chronic hepatitis are unknown. Lymphocytes are typically observed within the hepatic parenchyma, but the functional characteristics of these cells have not been defined. In this study, liver-infiltrating lymphocytes from two subjects with chronic HCV hepatitis were cloned at limiting dilution and tested for HCV-specific cytolytic activity using autologous target cells infected with vaccinia viruses expressing recombinant HCV Ag or sensitized with synthetic HCV peptides. In both subjects, HCV-specific, HLA class I-restricted CTL were identified that recognized epitopes in variable regions of either the envelope or nonstructural proteins. These results demonstrate the presence of HCV-specific CTL at the site of tissue damage in persons with chronic HCV hepatitis, and provide a means to evaluate the possible pathogenic role of these cells in HCV infection.
 ...
PMID:Intrahepatic cytotoxic T lymphocytes specific for hepatitis C virus in persons with chronic hepatitis. 138 23

In a chimpanzee model of acute type B hepatitis, at the time of onset of hepatitis B virus replication and before the development of immunity to hepatitis B virus, interferon is present in the plasma. This is followed by an increase in the display of HLA class I, but not class II proteins, on the hepatocyte membrane. In chronic hepatitis B virus infection, there is a low density of HLA class I protein display on the infected hepatocyte. Administration of alpha-interferon enhances HLA display and in many cases is followed by a transaminase elevation, seroconversion of HBe antigen to antibody and disappearance of hepatitis B virus DNA from serum, changes implying clearance of infected hepatocytes. Successful response to interferon therapy may be predicted by a rapidly rising serum beta 2-microglobulin, a component of the HLA class I molecule, during the first 2 weeks of therapy, before the rise in transaminases.
 ...
PMID:HLA class I antigens on the hepatocyte membrane during recovery from acute hepatitis B virus infection and during interferon therapy in chronic hepatitis B virus infection. 242 27

Studies on the quantitative expression of the Major Histocompatibility Complex (MCH) in hepatocytes chronically infected by Hepatitis B Virus (HBV) report that an increased expression of these antigens could be related to a good immunological response. In the present work we analyze the expression of the MCH antigens in cryostatic sections of liver biopsies taken from subjects (19 children) with various forms of HBsAg positive chronic hepatitis. A high expression of HLA class I antigens and a high degree of hepatocyte necrosis was evident in Chronic Active Hepatitis (CAH) and Chronic Lobular Hepatitis (CLH). On the contrary, subjects with histological diagnosis of Chronic Persistent Hepatitis (CPH) showed a low expression of such antigens. There was however, the difference that in subjects with high hepatic cytolysis and high expression of HLA class I antigens, serum HBV-DNA was clearly present in almost all the cases with CAH, but not detectable in all cases with CLH. The expression of HLA class II antigens and of Beta2 microglobulin was the same in all 19 cases. All cases with HBV-DNA positivity with high class I antigen expression had active hepatitis which seems to suggest that all attempts at viral clearance on the part of the immune system have been in vain. We hope our paper will be an additional parameter for evaluating the course of hepatitis during Interferon treatment.
 ...
PMID:Different expression of HLA class I antigens in liver of children with chronic hepatitis B, evaluated by immunohistochemical method. 269 19

The clinical presentation and outcome of 32 children with primary sclerosing cholangitis (PSC) are reviewed, the largest North American series. The majority of patients were diagnosed in their second decade (median age: 13 years). Four children presented before the age of 2 years, but none in the neonatal period. Seventeen patients had inflammatory bowel disease (IBD), all with colitis, 14 ulcerative colitis, and 3 Crohn's disease. Eight patients presented with chronic liver disease before clinical onset of IBD. Only 8 of 32 patients were jaundiced at presentation. Fifteen of 32 had a normal serum alkaline phosphatase (ALP) level at presentation. Nine children presented with features similar to those of autoimmune hepatitis. Cholangiography was performed in all cases and classified by a scoring system specifically developed for pediatric patients. Intrahepatic disease predominated; in only three cases a common bile duct stricture was identified requiring stenting. Findings on the initial liver biopsy were classified according to Ludwig's criteria for staging PSC: there were 15 biopsies in stages 1 to 2 and 17 biopsies stages 3 to 4. HLA class I and II antigens were determined in 27 patients. An increased incidence of HLA B8 and DR2(15) but not DRw52a (DRB3*0101) was found. Anti-neutrophil cytoplasmic antibody (ANCA) was positive in 10 of 24 patients tested. Survival analysis indicated that a later age at presentation, splenomegaly, and prolonged prothrombin time (PT) at presentation were significant contributors to the prediction of poor outcome (i.e., death or listing for transplantation). Liver transplantation was successfully performed in seven children. Physicians must maintain a high index of suspicion of PSC in any child or young adult presenting with chronic liver disease, especially in the presence of IBD, even with a normal serum alkaline phosphatase level.
 ...
PMID:Primary sclerosing cholangitis in 32 children: clinical, laboratory, and radiographic features, with survival analysis. 759 Jun 57

Hepatitis C virus (HCV) is a major cause of posttransfusion and community-acquired hepatitis, and a majority of individuals infected with this virus will subsequently develop chronic hepatitis. Characterization of the host immune response to this infection is an important first step that should facilitate the development of immunomodulatory agents and vaccines. Cellular immune responses, especially those mediated by cytotoxic T lymphocytes (CTL), are important in the control of many viral diseases. In this study, liver-infiltrating lymphocytes from persons with chronic HCV hepatitis were examined for evidence of HCV-specific CTL by using target cells infected with recombinant vaccinia viruses expressing the HCV core, E1, E2, and part of the NS2 proteins. Bulk expansion of liver-derived CD8+ lymphocytes resulted in the detection of HCV-specific CTL activity, whereas activity could not be found in CD8+ lymphocytes expanded from peripheral blood. Epitopes recognized by these CTL were defined by using CTL clones obtained by limiting dilution and target cells sensitized with synthetic HCV peptides. Four distinct HLA class I-restricted epitopes were identified, including two epitopes in the amino-terminal portion of the core protein. These studies provide evidence that the highly conserved core protein is a target for HCV-specific CTL and identify CTL epitopes within the more highly variable E2 envelope protein. Our studies also suggest that HCV-specific CTL are localized at the site of tissue injury in infected persons with chronic hepatitis. Identification of the epitopes recognized by HCV-specific CTL will facilitate exploration of their role in disease pathogenesis and may provide information useful in development of therapeutic interventions or vaccines.
 ...
PMID:Hepatitis C virus (HCV)-specific cytotoxic T lymphocytes recognize epitopes in the core and envelope proteins of HCV. 769 74

In hepatitis C, both susceptibility to infection and the course of disease may depend on differences in the immune response. As the major histocompatibility complex (MHC) plays a crucial role in antigen presentation, we investigated a possible relationship between susceptibility to hepatitis C virus (HCV) infection and human leucocyte antigen (HLA) alleles. Therefore, phenotype frequencies of HLA were compared in 186 anti-HCV positive patients with end-stage renal disease (ESRD) to 328 anti-HCV negative patients with ESRD. HLA class I alleles were determined serologically and HLA class II alleles (DRB1, DQA1, DQB1) by the polymerase chain reaction sequence-specific oligonucleotide (PCR-SSO) technique. Additionally, in anti-HCV positive patients we looked for a relationship between the activity of hepatitis C (indicated by elevation of transaminases or the presence of viremia) and HLA determinants. For the three criteria (antibody status, elevation of transaminases and viremia) a significant association to HLA alleles was not found in patients with ESRD. This suggests that neither susceptibility to HCV infection nor the biochemical activity of hepatitis and HCV-RNA positivity seem to be strongly related to HLA status in Caucasian patients with end-stage renal disease.
 ...
PMID:No significant influence of HLA determinants on susceptibility to hepatitis C virus infection in Caucasian patients with end-stage renal disease. 902 18

Cytotoxic T lymphocytes (CTL) are closely related to the mechanism of liver injury in chronic viral hepatitis. Recently, it has been suggested that antigen-specific T cell activation requires both presentation of antigen by major histocompatibility complex (MHC) molecules and the delivery of costimulatory signals. Such signals are provided by B7/BB-1, one of the most important accessory molecules, sufficient for causing antigen-specific MHC-restricted T cell activation. To evaluate the role of B7/BB-1 in chronic hepatitis C, we immunohistochemically studied its expression in liver tissues obtained from 61 patients with hepatitis C virus (HCV) infection and compared them based on hepatitis activity. In HCV-infected liver, B7/BB-1 was strongly expressed in the cytoplasm of hepatocytes. B7/BB-1-positive cells accompanied liver-infiltrating lymphocytes and were mainly detected in the periportal region. B7/BB-1 expression was closely correlated with the activity of viral hepatitis as evaluated from scores of periportal or intralobular inflammation and necrosis, or serum alanine transferase (ALT) levels. Further study by immunostaining with anti-HCV core and anti-human leukocyte antigen (HLA) class I antibody showed B7/BB-1 positive cells near HCV core antigen- and HLA class I-positive cells, with B7/BB-1-positive cells mostly included among HLA class I-positive cells. These findings suggested that B7/BB-1 expression by hepatocytes may be induced by HCV infection and may trigger generation and activation of CTL, which may cause damage to HCV-infected HLA class I-expressing hepatocytes.
 ...
PMID:B7/BB-1 expression and hepatitis activity in liver tissues of patients with chronic hepatitis C. 904 24

The human leukocyte antigen is a crucial genetic factor that initiates or regulates immune response by presenting foreign or self antigens to T lymphocytes. The aim of this study was to investigate whether HLA polymorphism is associated with the onset or progression of liver injury in chronic hepatitis C virus (HCV) infection. We determined HLA class I antigens and class II alleles in 130 hepatitis C virus (HCV)-infected patients (33 carriers with persistently normal alanine transaminase [ALT] values and 97 patients with chronic liver disease [CLD]). HLA class I (A, B) was typed serologically, and class II (DRB1, DQB1) was typed by means of polymerase chain reaction-restriction fragment length polymorphism methods. The frequencies of DRB1*0405 and DQB1*0401 were higher in HCV-infected patients than in uninfected subjects. Among HCV-infected patients, the frequencies of B54, DRB1*0405, and DQB1*0401 were significantly higher in patients with CLD than in those carriers with persistently normal ALT values, whereas DRB1*1302, DRB1*1101, and DQB1*0604 were more frequently found in carriers with persistently normal ALT values than in patients with CLD. From extended haplotype analyses, in carriers with B54-DRB1*0405-DQB1*0401 haplotype, the risk of having liver injury was 13.2 times greater than in carriers with DRB1*0405-DQB1*0401 but without B54 [P = 0.0015, Haldane odds ratio = 13.2 (95% confidence interval, 1.7-103.8)]. In contrast, carriers with B44-DRB1*1302-DQB1*0604 had a 12.7-fold lower relative risk of developing liver injury compared to those with the haplotype containing B44 but not DRB1*1302-DQB1*0604 [P = 0.0076, Haldane odds ratio = 0.079 (0.009-0.695)]. Our findings show that extended haplotypes including class I B54 are closely associated with the progression of liver injury, whereas extended haplotypes including class II DRB1*1302-DQB1*0604 are associated with low hepatitis activity in chronic HCV infection.
 ...
PMID:Influence of HLA haplotypes on the clinical courses of individuals infected with hepatitis C virus. 942 43

In the present study, intrahepatic CD8+ lymphocyte infiltrates as well as HLA class I and CD54 (ICAM-1) antigen expression at both tissue and serum levels were evaluated in 54 untreated patients with chronic hepatitis C stratified on the basis of histological diagnosis (Chronic Persistent Hepatitis/Chronic Lobular Hepatitis -CPH/CLH- and Chronic Active Hepatitis -CAH-: 22 and 32 subjects, respectively). The relationships between soluble HLA-I (sHLA-I) and ICAM-1 (sICAM-1) serum levels and their membrane-bound counterparts, CD8+ liver infiltration and serum alanine aminotransferase (ALT) were also studied. A strong HLA-I and CD54 tissue expression, associated to the presence of CD8+ cell infiltrates in necro-inflammatory areas, and elevated sHLA-I and sICAM-1 serum amounts were observed in all patients. At the same time, no difference was found at tissue level between the two groups of patients with respect to the mean scores of HLA-I and CD54 expression, while CAH subjects displayed a significantly higher CD8 periportal and lobular reactivity in comparison to the other subset. Serological assays outlined higher values of circulating HLA-I molecules in CPH/CLH patients and higher sICAM-1 levels in the CAH group. Finally, a negative correlation was found between sHLA-I and ALT in CAH subjects while, in all patients, sICAM-1 positively correlated with both CD8 tissue infiltration and ALT. Our findings confirm the occurrence of an immune activation status during chronic hepatitis C and suggest that sHLA-I molecules might play a down-modulating role on immunoresponsiveness of these patients.
 ...
PMID:Immunoresponsiveness in chronic hepatitis C patients: correlation between tissue and serum findings. 973 40

Two patients undergoing liver transplantation for classical end-stage primary biliary cirrhosis (PBC) are described, who went on to develop de novo autoimmune hepatitis (AIH) in the transplanted liver. The presentation, in both instances, was with malaise and lethargy. Markedly elevated serum transaminases were found, together with a raised serum IgG and/or globulin fraction and histological features on liver biopsy typical of AIH. Both cases had had changes in their immunosuppressive therapy before the onset of AIH episodes, and both rapidly responded to reinstitution of steroid therapy. The finding, in each case, of a coincidental multiple HLA class I allele match between the recipient and their liver donor suggests that HLA class I-restricted mechanisms may play an important role in the pathogenesis of AIH.
 ...
PMID:Development of autoimmune hepatitis following liver transplantation for primary biliary cirrhosis. 1100 37


1 2 3 Next >>